1) Field of the Invention
The invention herein relates to an improved method of sluice gate valve fabrication, wherein a cylindrical rod of an appropriate diameter is first forged into a sluice gate body blank, the rough edges of which are removed by punching, and then a shaft having the same diameter is aligned with an abraded welding surface of a pivot stem at the lower end and conjoined to it by friction welding; as such, the present invention minimizes forging mold volume and, furthermore minimizes the overall quantity of material utilized for sluice gate valve fabrication to thereby reduce the production costs of the manufacturer
2) Description of the Prior Art
In conventional sluice gate fabrication, casting is the predominant production method; however most of the components fabricated by such methods have surface pitting (sand holes) that easily results in liquid and gas leakage during usage; furthermore, since the shaft of the sluice gate is excessive in length, the molten material cannot be equally distributed during sluice gate casting and, furthermore, the lengthy shaft cannot be cast at an exact perpendicular angle, this readily results in incorrect shape flaws; in view of this, manufacturers are researching and developing forged fabrication methods.
The improved sluice gate valve fabrication method based on forging typically involves a cylindrical rod Axe2x80x2 of a certain diameter that is forged into a body 21 of a sluice gate as well as a shaft 22 section at the bottom of the body 21; the rough edges T formed by casting along the blank 2xe2x80x2 are then removed by punching to form the completed sluice gate 2; however, in the fabrication method of such sluice gates 2, since the width of the unforged cylindrical rod Axe2x80x2 has to be sufficient enough to become forged into the circular shape of the body 21, the cylindrical rod Axe2x80x2 must be of a larger diameter; as such, since the diameters of the cylindrical rod Axe2x80x2 before and after punching differ considerably, much forged material is wasted following the punching of the shaft 22; furthermore, since the shaft length of the finished product varies and each shaft length requires a different forming mold, the production cost of the manufacturer is increased.
In view of the drawbacks associated with the conventional fabrication method, the inventor of the invention herein conducted extensive research and development that culminated in the successful development of the present invention.
The primary objective of the invention herein to provide an improved method of sluice gate valve fabrication, wherein a cylindrical rod of an appropriate diameter is first cut and then the cylindrical rod is forged into a one-piece blank for a disk-shaped sluice gate body having pivot stems; the raw edges along the periphery of the blank are then removed by pressure punching to form the body of the sluice gate; and a shaft having the same diameter as the pivot stem at the lower end is aligned with and conjoined to it by friction welding; as such, the quantity of material utilized for the cylindrical rod is minimized.
Another objective of the invention herein to provide an improved method of sluice gate valve fabrication, wherein since the sluice valve dimensions are based on world standard specifications, the sluice valve molds are of uniform sizes; the pre-forged sluice gate body portion and the friction welded shaft section enable meeting the shaft length requirements of users because shafts of different length specifications can be freely selected, with different sized molds only needed for changes in the shaft section to thereby minimize shaft mold volume.